Boat propulsion apparatus



p 1940- "A. RONNING 2,213,610

' non PROPULSION APPARATUS Filed April 25, 1938 2 snets-sneet 1 llllll l INVENTOR I ADOLPH EONN/A/ ATTORNEY A. RONNING BOAT PROPULSIOI! APPARATUS Filed April 25, 1938 2 Sheets-Shee't 2 INVENTOR 400 L PH ,eo/wvnva ATTdRNEY Patented Sept. 3, 194i? 2 D UNITED stares PATENT OFFLCE.

i non-r rnorfiisizi: APPARATUS Adolph Romaine, Minneapolis, Application April 25, 1938, Serial No. 204,061 1 Claim. (01. 115-11) My invention relates to apparatus for the proouter ends by an annular rim of relatively wide pulsion of boats and water craft of'various kinds, material in order to thus substantially confine and more particularly the invention provides the water acted upon by the blades and cause all improvements in the type of propulsion apparatus of said water to be urged rearwardly in order to known generally as outboard motors. obtain the maximum forward thrust from the Apparatus of this kind consists usually of a blades. I p motor of the internal combustion type and a pro- Another, and important, object is to provide a peller which is supported by a standard from the multiple or tandem propeller assembly wherein motor and rotates on a substantially horizontal two or more similar propellers are disposed one 'andfore and aft extended axis below the water. behind the other, and arranged to rotate in eitheri Also included as basic elements of the assembly the same, 'or opposite, directions. In'either case are the water circulating system and exhaust the forward thrust and propelling power of the discharge system for the motor, which systems assembly is multiplied-and, in the case of OPP are conveniently arranged to terminate in the site rotation of the propellers, the usual lateral transmission housing carrying the propeller in creep" of the boat propelled by the apparatus order that the cooling water may be circulated in is prevented. This lateral creep is occasioned a continuous stream picked up from, and reordinarily by the difierence in water pressures and turned to, the water surrounding the boat, and so densities above and below the propeller, and the that the exhaust gases may be discharged below aforesaid rotation of the propeller will neutralize 30 water level for the purposes of reducing exhaust the effect to such extent as to prevent said creepnoises of the motor. ing motion.

The primary object of my invention is to pro- Another object is to provide a propeller assemvide, in an apparatus of this kind, an improved bly embodying a guard and weed cutting means propeller assembly wherein the propeller operates as described, and wherein the propeller is driven 25 within the confines of a guard device which inthrough a friction type overload clutch of such cludes a forwardly disposed cutting bar extended nature as to allow the propeller to be automatia across the frontal face of'the propeller, and cocally uncoupled from its driving shaft should operating with cutting edges formed on ,the the weeds or other larger material jam in the blades thereof in such manner that a shearing guard and prevent the propeller from rotating.

efiect will be produced in order to enable the pro- Damage to the propeller from this cause is thus peller to cut through weeds and othermatter prevented, and the clutch, is so arranged that in the water. which would otherwise become enthe overload or pressure required to uncouple the tangled in the propeller, and possibly stop or propeller may be readily adjusted as may be damage the same. required.

35 Another object is to provide, for a propeller A further object of the invention'is to provide 35 assembly as described, a guard device which ina propeller, guard, and transmission assembly cludes a rearwardly trailing foot member extendwhiclfmay be supported readily from the standing beneath the propeller in order to protect the ard depended from the motor, and which emsame against contact with rocks or other obbodies means for'the discharge of the exhaust 40 structions the water, and which further ingases of the motor rearwardly substantially along cludes vertically disposed and relatively flat porthe. axis of rotation of the propeller, or protions disposed edgewise to the directions of travel pellets, in order to take advantage of the sucof the boat and apparatus in order to afford a. tion existing behind the propeller for forcibly and rudder effect to facilitate steering. effectively drawing the exhaust gases from the 45 Another object is to provide a propeller guard motor. This assembly further makes possible the *5 assembly of this kind which is arranged for con-' use of a cooling water circulating system wherein venient removal and replacement on the supportno mechanical pump need be employed but, ining parts of the assembly, by virtue of the use of stead, the flow of the exhaust gases may be dove-tailed connections for the guard and lock utilized to set up a suction sumcient to circulate 5 screws which normally prevent disengagement of the water. these connections but which may be readily re- Still a further object is to provide a novel asmoved when it is desired to disengage the guard. sembly'of this kind in which a rear bearing mem- Another object is to provide an improved. proher for the propeller shaft is threaded in place to peller for an apparatus of this nature, in which facilitate the assembling of the parts and which 66 the propeller blades are enclosed around their hearing member is then employed as the supvention.

. apparatus shown in Fig. 1.

Fig. 2 is an enlarged frontal elevation of the lower portion of the apparatus of Fig. 1, showing the propeller and the weed cutting guard device.

Fig. 3 is an enlarged vertical and fore and aft cross section through the lower portion of the Fig. 4 is a. horizontal cross section along the the line 4-4 in Fig. 3.

Fig. is a view similar to Fig. 3, but showing an assembly embodying tandem propellers rotating in the opposite direction.

Fig. 6 is a similar view but showing means for driving the tandem propellers. in opposite directions.

It may be here noted that the present invention includes subject matter described and claimed in my copending application filed April th, 1938, and given Serial No. 202,258, to which application attention is invited 'for comparative purposes.

Referring now with more particularity to Figs. 1 through 4 of the drawings, A designates a conventional outboard motor which includes the tubular standard B for supporting the transmission unit or housing C and which standard .is rotatably supported at D in a bracket E. This bracket E is used for clamping and supporting the entire assembly from the side, rear, or other 'part of the boat, and the rotatable support at D permits the entire assembly to be rotated about a vertical axis by means of the handle F for purposes of steering the boat. The bracket E also permits upward and rearward tilting of the assembly, and it will be assumed, for convenience in this description, that the motor operates ordinarily in the position shown with the standard B vertically disposed.

The drive shaft G of the motor A depends through the standard B and enters the transmission unit C where it is arranged to rotate the propeller shaft H by means of the bevel gears I. The drive and propeller shafts G and H are journaled in bearings J, and oil seals K are provided so that the chamber L may be oil filled for lubricating the parts. The transmission unit C is releasably secured on the lower end of the standard B by a clamp M, and is substantially tubular in form, terminating at its lower end in 'said chamber L and in the fore and aft extendedbearings J. The propeller shaft H extends forwardly from this unit C, as shown. The propeller 1 includes the hub 8, radially ex- .tended blades 9, and the annular rim III which is supported at the outer extremities of the blades concentrically with the hub. The said hub 8 is journaled freely on the forward end portion of the propeller shaft H, and has its frontal end ll angularly and annularly beveled as shown, to engage the complementally beveled rear end l2 of a clutch collar I3 which is keyed at I4 on the shaft. A friction ring or washer I5 is interposed between the hub and collar, and an expansion coil spring I6 located in an annular recess I! in the hub 8 is braced against a fixed washer l8 on the propeller shaft to normally and yieldably urge the propeller hub forwardly into frictional engagement with the clutch collar [3. This collar is retained in place by a nut l9 threaded on the frontal end of the propeller shaft H, and the tension of the spring I 6, hence the driving effect of the clutch, may be varied by adjusting this nut. The frictional engagement between the hub 8 and the clutch collar I3 is sufiicient, under normal load conditions, to cause the propeller .1 to rotatewith the propeller shaft H. However, should the propeller be jammed or entangled by weeds or the like the clutch will release, allowing the shaft H to turn free without damaging either the propeller or driving parts.

The propeller rim I0 is widened parallel with the axis of rotation of the propeller, and is of forwardly rounded and rearwardly tapered across section shape in order to move through the center with very little resistance. The rim, thus formed, serves to prevent outward displacement of the water radially of the propeller due to action of the blades 9, and thus ensures that the water will be moved rearwardly with the greatest possible driving thrust thus secured from the propeller.

The frontal and leading edges of the propellerblades 9 are extended straightly and radially, and are sharpened in order to have a cutting effect on weeds and the like with which the propeller might come in contact. To facilitate this cutting action, as well as to guard the propeller, I provide a guard frame or device designated generally at 2| made up of the integrally formed frontal guard and cutting bar 22, the upper and lower rearwardly turned portions 23 and 24,.and the upwardly turned mounting portion 25 on the lower portion 24. The guard thus formed de- -fines a substantially rectangular opening 26 in which the propeller I may readily rotate with its rim In just clearing the portions 23 and 24, and the cutting edges 20 of the blades 9 operating just behind the rear edge of the bar 22 which extends vertically and diametrically across the face of the propeller, as shown.

The guard 2| is removably mounted and supported on the transmission housing 0 by means of laterally extended dovetailed grooves 21 which receive complementary, laterally extended, dovetailed ribs or tenons 28 cast on the frontal and lower sides of the housing C. These connections, as shown in the drawings, are three in number, with one located at the upper extremity of the mounting portion 25 and two spaced along the rear end of the upper guard portion 23 which is widened rearwardly in a vertical direction to present the forwardly and downwardly sloping frontal edge 29. This construction also provides a substantial lateral surface or area which is of value in the rudder effect of the assembly necessary for steering the boat.

The upper and lower dovetailed connections 21-28 are provided with set screws 30 which are threaded in the guard 2| in such position that they may be turned into locking engagement with the ribs or tenons 28.

The guard may thus be, slipped into place laterally, or from. the side of the unit is a whole, and when located it may be locked by turning up the screws 30. By loosening these screws the guard may-then be readily removed at any time. Preferably the grooves 21 and ribs 28 are tapered lengthwise in order to thus bind and more rigidly secure the guard in place.

reach the transmission housing easing of the motor and The entire frontal and lower edge portion of the guard 2| is rounded, .asindicated, in order to move through the water with little resistance, and the lateral rear edges 3| of the frontal or cutter bar 22 are sharpened in order to cooperate with the cutting edges of the propeller blades. As a result there will be a shearing action between the blades 9 and this bar 22, such as will readily cut through weeds and the like which may be encountered in the water.

The bar 22 also serves as a guard to prevent injury to the propeller should it come in contact with an obstruction in the water, and the upper and lower portions 23 and 24 similarly serve to protect the propeller. The lower portion 24, or foot, will be of particular service to guide the propeller over obstructions. This protective function of the guard 2| is furthered and enhanced by the rim III which also serves to protect the blades 9.

The frontal bar 22has a medially'located and rearwardly opening recess 32 which provides clearance for the nut |9.at the end of the propeller shaft.

The exthaust gases from the motor A are carried down the tubularstandard B until they C, where they may emerge from an opening 33 in the rear thereof. A nozzle member 34 is provided and has its large inlet or mouth portion mounted over this opening 33 so that the gases will flow; rearwardly into the nozzle. The nozzle then has the downwardly turned offset portion 35 which carries the gases rearwardly, charges them through the rearwardly turned exhaust or discharge end 36 located exactly in line with the axis of rotation of the propeller J. The nozzle is mounted as described, by means of ascrew 31 which is screwed into the housing 0 above the opening 33 and by another screw 38 passed through a lug 39 in the lower partof the nozzle, and screwed into the rear bearing J. Thisrear bearing is screwed into the rear end .of the housing C as shown at cess to the chamber gears I and shaft H. The screw 38 may be reached for removal and replacement through the discharge and 36 of the nozzle.

The forward movement of the assembly through the water, together withthe rearward movement of the water by the propeller I, will cause a suction to be exerted at the nozzle discharge end 36 such as will cause the exhaust gasesto be rapidly and forcibly drawn from the engine and discharged into the water.

effect: is enhanced bythe Venturi-like action which takes'place due to the outward flare at 4| of the inner surface of the nozzle at its discharge end. The advantageous effects .and results of this exhausting ofthe gases have been. pointed out inmy copending application hereinbefore identified, and include the complete scavthe elimination of exhaust noises. It is also possible, due to this action and as detailed in my copcnding fipp fltion, to eliminate the usual mechanical-water pump by utilizing v.the flow of exhaust gases to circulate the cooling-water.

For this purpose a water inlet pipe 42.is provided with an inlet at 43 for, the water surrounding the housing C, and this pipe leads the water upto the cooling system of the motor A.

The used water is then carried and finally disare keyed as in' order that it may be removed when required to give ac- L, and-for assemblin the tical except that the neutralizes water spin ,shown) in either of the and these ducts terminate in collars surround the propeller shafts H'-H".

downwardly through anoutlet pipe 44 which communicates at 45 with a chamber 46 which is formed around the standard Bby an annular casing 41 afiixed thereto. The water may enter the standard B from this chamber 46 through vents or ports 48 which, have the downwardly and inwardly extended overhead guides or deflectors 49. The pipes 42 and 44 pass upwardly through the standard B as shown.

The foregoing arrangement is thus such that the downwardly rushing exhaust gases will. strike the'deflectors 49 to set up a Venturi-action reblades 9-9, and the annular surrounding rims Hi -"l and the frontal propeller 1 operates within a guard 2| substantially as hereinnefore described. However, the foot portion 24" of this "guard 2| is extended rearwardlybeneath the rear propeller I in order to protect the same from obstmction in the water." The transmission, housing C is substantially the same as that previously described, and carries the drive shaft G operating the propeller shaft H through the gears I' and the propeller shaft extends both forwardly and rearwardly from. the housing in order that the propellers maybe mounted on opposite ends thereof, as shown. The propellers at |4--| 4 on the propeller shaft H, and no overload clutch is employed in the assembly shown, though it may be used if desired. The guard 2| is mounted on the housing C by the dovetailed grooves and tenons in exactly the manner hereinbefore described.

In the assembly shown, both propellers 1* --'l are rotated in the same direction, and the forward thrust thus afforded is approximately doubled. In Fig. 6 the assembly is substantially idenpropeller shaft H" is dividedinto two sections which are journaled, together by the pilot bearing 50. The beveled gears I" drive the frontal shaft section and frontal propeller 1 in one direction, while the rear shaft section and rear propeller 'l are rotated in the opposite direction by a separate beveled gear 5| engaging the 'drive gear as shown. This action also substantially doubles the driving thrust over the single propeller assembly, and in addition,

and prevents the lateral creeping of the boat which is caused by the differences in water resistance above and below the propellers.

"rhe exhaust gases from the motors (not assemblies of Figs. 5 and 6 are carried rearwardly "and downwardly ,by duct members 52 secured by screws 53- over the openings in therear of the housings C'-C", 56 which The rear propeller hubs carry enlarged tubular drums 54 which rotate behind the collars 58,. and in which fan blades 55 are radially disposed. These blades act, as the propellers rotate, to set up a suction to draw the gases rearwardly and discharge-them into the water behind the propellers, and the water circulating system may be the same as that hereinbefore described, or a mechanical water pump may be used if desired. This fan assembly for drawing the gases and other waste products outwardlyis also disclosed in my copending application above referred to.

The frontal propellers I -1 in both Figs. 5

and 6 cooperate with the frontal bars 2222 of the guards 2 l"-2| to cut weeds or similar material in the water, and thus clear the way for the rear propellers, as will be understood. Of course, more than two propellers may be used in tandem if so desired.

It is understood that I may vary from the specific assemblies and structures herein described, provided that such variations fall within the scope of the appended claim. Having thus fully disclosed my invention, what I claim as new and desire to secure by Letters Patent is:

A boat propulsion apparatus comprising, a power driven propeller means, a supporting device for the propeller means, a guard frame, and dovetailed detachable mounting means supporting the guard frame from the supporting device in position for protecting the upper,'frontal and lower sides of the propeller.

' a ADOLPH RUNNING. 

